Birth and death of Stars
There are 200-400 billion stars (suns) in our galaxy and they all follow a very predicted life cycle. 'The stars birth' has now existed for billions of years and the star will follow a predicted path that the star will follow. All of the stars are made of cold molecular hydrogen and our sun is the closest star.
Life Cycle of a star
As Figure 1 above shows us that in the start the stars were huge clouds of hydrogen also known as Solar Nebulae this is the nursery of the stars. After millions and millions of years particles started to gather as the distance boomed through a cloud. Discs were then produced when the matter was compressed and gathered. Atoms of force which was also known as a proto star was pressured and heated until eventually a star was born. A proto star is a large mass that forms by contraction out of gas. After the star is born it will start to emit heat and light. Balanced forces will predict the size of the star (as per figure 2).
The stars then form main sequence stars. As the stars start to expand they will continue to grow as the core stars to run out of hydrogen followed by helium. Main sequence stars are medium size stars and will tend to burn steadily, unless fuel supply is unavailable. As average sized stars spread out and expand to find more fuel they transform into red giants. Red giants have cool surface areas and can't expand much more. When the fuel of the star is used up embers breakdown to form white dwarfs. White dwarfs then cool and produce a black dwarf. After the red giant phrase larger stars are transformed into a super giant. Super giants can then be then exploded other known as a supernova and form either a neutron star or black hole. A neutron star as figure 1 says is when the core collapses and becomes very dense. Figure 1 also tells us that a black hole is also when the core completely collapses and vanishes. Both of these circumstances depend on the size of the star.
The stars then form main sequence stars. As the stars start to expand they will continue to grow as the core stars to run out of hydrogen followed by helium. Main sequence stars are medium size stars and will tend to burn steadily, unless fuel supply is unavailable. As average sized stars spread out and expand to find more fuel they transform into red giants. Red giants have cool surface areas and can't expand much more. When the fuel of the star is used up embers breakdown to form white dwarfs. White dwarfs then cool and produce a black dwarf. After the red giant phrase larger stars are transformed into a super giant. Super giants can then be then exploded other known as a supernova and form either a neutron star or black hole. A neutron star as figure 1 says is when the core collapses and becomes very dense. Figure 1 also tells us that a black hole is also when the core completely collapses and vanishes. Both of these circumstances depend on the size of the star.
Size of the stars
Stars come in 3 major categories according to their size. The size depends on many things but it mostly depends on the fusion that was produced by energy. This energy gets pushed outward which is balanced between the inward pull of gravity. A large star will have a large amount of mass or other known as nebula. The size of the nebula is very important to help form a star. A small star will have less mass (0.1% of our sun) as it is smaller in size. Our sun emits a yellow light which is a medium heat. Blue/white stars become much hotter (very hot) and red/orange stars are much cooler suns. The colour and mass of the stars will tell the temperature of the stars and how fast they will burn their fuel. The Bigger mass a star has the more chance of it burning more quickly. The size of the stars will also predict how long they live for and die. A smaller sized star will slowly burn their fuel and change rather then larger sized stars.
H-R Diagram
The H-R Diagram or other known as the Hertzsprung-Russell Diagram tells astronomers the type of the stars, the colour, temperature and the stage of development. Figure 3 demonstrates the main sequence in the middle strip of the diagram. This Strip is hydrogen burning and converting to helium, this will depend on the mass of the star. The super giants are very big stars at the top corner of the diagram. These stars may appear red because of their size. Giants are the same as super giants however the super giants are much bigger. At the bottom left corner of the diagram are white dwarfs this is what stars are like after all their nuclear fuel is wasted. Once the white dwarfs gets to the burning stage they start to eject the outer side of the star called the planetary nebula this makes it very hot and dense.